# -*- coding: utf-8 -*-

# Define here the models for your spider middleware
#
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/spider-middleware.html
import base64
import random
from scrapy.downloadermiddlewares.useragent import UserAgentMiddleware
from scrapy import signals

from KeywordSpider.settings import mysql_conf
import pymysql as MySQLdb
import requests

from scrapy import signals

from KeywordSpider.settings import mysql_conf, redis_conf


class KeywordspiderSpiderMiddleware(object):
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, dict or Item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Response, dict
        # or Item objects.
        pass

    def process_start_requests(self, start_requests, spider):
        # Called with the start requests of the spider, and works
        # similarly to the process_spider_output() method, except
        # that it doesn’t have a response associated.

        # Must return only requests (not items).
        for r in start_requests:
            yield r

    def spider_opened(self, spider):
        spider.logger.info('Spider opened: %s' % spider.name)


class KeywordspiderDownloaderMiddleware(object):
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.

        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    def spider_opened(self, spider):
        spider.logger.info('Spider opened: %s' % spider.name)



"""避免被ban策略之一：使用proxy池。
使用注意：需在settings.py中进行相应的设置。
DOWNLOADER_MIDDLEWARES = {
    'scrapy.downloadermiddleware.useragent.UserAgentMiddleware' : None,
    'keywordSpider.middlewares.RotateUserAgentMiddleware' :400,
    'scrapy.downloadermiddleware.httpproxy.HttpProxyMiddleware':543,
    'keywordSpider.middlewares.ProxyMiddleware':125
 }
"""
import os
import random
import socket
import re
class ProxyMiddleware(object):
    def __init__(self):
        self.proxy_pool = [{'ip_port': '123.160.246.41:3130'}]
        try:
            s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
            s.connect(('baidu.com', 80))
            if s.getsockname()[0] in ['123.160.246.41', '218.28.2.162']:
                self.proxy_pool = [{'ip_port': '127.0.0.1:3130'}]
        except Exception as e:
            print(e)
            rep = '^((192\.168|172\.([1][6-9]|[2]\d|3[01]))(\.([2][0-4]\d|[2][5][0-4]|[01]?\d?\d)){2}|10(\.([2][0-4]\d|[2][5][0-4]|[01]?\d?\d)){3})$'
            output = os.popen('/sbin/ifconfig|grep "inet "|grep -v "127.0.0.1"|xargs').read()
            tmp_ip_info = re.split(' |:', output)
            for i in tmp_ip_info:
                rep_ip = re.search(rep, i)
                if rep_ip and rep_ip.string in ['172.16.13.10', '172.16.13.11']:
                    self.proxy_pool = [{'ip_port': '127.0.0.1:3130'}]
        finally:
            s.close()


    # overwrite process request
    def process_request(self, request, spider):
        # Set the location of the proxy
        thisproxy = random.choice(self.proxy_pool)
        request.meta['proxy'] = "http://" + thisproxy["ip_port"]

